I also find that FreeBSD removed this specifier in [2].
Should we remove this?

[1] https://www.postgresql.org/message-id/c763235a2757e2f5f9e3e27268b9028349cef659.camel%40oopsware.de
[2] https://reviews.freebsd.org/D7306
-- 
Regrads,
Japin Li